RTL' IMO maybe you could say something like "thank you for sharing that but since you divorced me I have no interest in your romantic life other than it's impact on our D". Remember boundaries? Your ex W seems to need to know she can still hurt you. Don't allow her to hurt you anymore. She has a boyfriend yet she still gets a kick out of students and coworkers hitting on her. Apparently people see her as "available". It says something about her realationship with the BF, the one who mentioned marriage, that so many people see her this way.
